Based on the extension of the file, the appropriate HTTP Handlers gets loaded which is mapped to the extension and is responsible for processing the ASP. This interface provides one method ProcessRequest and a property IsReusable. ProcessRequest - This is a method which gets called when the request is received. Inside this method, you can call the HttpContext object which is passed as a parameter to the method.
NET application and designed some useful functionality or feature set that you wanted to be able to easily reuse in another ASP.
NET offers different tools for componentizing different types of functionality. The two most common tools for reuse in ASP. User Controls and custom, compiled server controls for user interface elements and functionality. NET class libraries for business logic and data access code.
For now, just understand that HTTP modules are classes that can be configured to run in response to events that fire during the request for an ASP. An HTTP handler is a class that is responsible for rendering a particular resource, or a particular type of resource.
In fact, each time you add an ASP. NET Web page gets dynamically compiled at run time, it directly or indirectly inherits from System. Page, which happens to be a HTTP handler implementation.
This is true irrespective of whether you take the inline or code-behind strategy. As you know, an ASP. There are times, though, that we need to write code that is orthogonal to a single Web page, code that applies to all pages in an application. For example, we might want to track the order with which each user moves around our Web site.
This approach, however, is hardly maintainable or reusable. Writing a custom httpmodules time we add a new ASP. Such reuse and maintainability is quite possible with HTTP modules and handlers. In this article, we are going to examine a set of HTTP modules and handlers that have been designed to make error logging a highly maintainable and reusable exercise.
The goal of this article is to demonstrate how HTTP handlers and modules can be used as a very high-level form of componentization, enabling entire sets of functionalities to be developed, packaged, and deployed as a single unit and independent of Web applications.
ELMAH illustrates how HTTP modules and handlers can be used to provide a high degree of componentization for code that is orthogonal to the Web application such as application-wide logging. NET Web application without any need for recompilation or redeployment.
No matter how well written and tested a particular Web application may be, things will still go awry every now and then. It may not be your code at fault, it could be that the e-mail server is not responding, or some corruption of data causes a cryptographic failure.
Regardless of the reason, when an exception occurs, especially on a live site, it is important that the details of the exception are recorded in order to assist with diagnosing the problem. ELMAH provides a mechanism for centralized error logging and notification.
Whenever an exception occurs in an ASP. This may include recording the details of the exception to a database, sending an e-mail to an administrator, or both. It simply records the details of unhandled exceptions. NET Web application, any unhandled exceptions raised in this application are logged.
But behind the scenes, ELMAH will have detected that an unhandled exception occurred and recorded the details. The Error event is raised whenever an uncaught exception bubbles up during request processing be that from a. Bear in mind that a lot of ASP.
NET applications incorrectly implement custom error pages and handling by calling the Server. Clearing the error will prevent the Error event from firing as well as being reported to the client and so ELMAH will never get a chance to log the exception.
Rather, it is intercepted by the ASP. There is a Web interface to the log, which can provide a list of all unhandled errors, as well as details about a particular error see Figures 1 and 2. Viewing the Error Log Figure 2.
Viewing an error This error log can also be rendered as RSS, thereby allowing an administrator to receive notifications through her favorite RSS aggregator when an error has occurred see Figure 3.
For brevity, this article touches upon only a subset of the features of ELMAH, focusing on the key components. The complete code is available for download with this article and we encourage you to study it thoroughly to get at the implementation details. While the Event Log is a suitable backing store for concise exception information for a desktop application, most Web applications—especially those being hosted on a shared server at a Web hosting company—steer clear of the Event Log because using the Event Log requires special permissions to be established to allow the ASP.
NET application to write to the Event Log. How the EMAB is used to record exception information strongly influences the maintainability and reusability of the Web application. NET Web page, making it anything but maintainable or reusable. This approach offers a more loosely coupled, maintainable, and reusable architecture, as the exception publishing code does not touch any ASP.So we don't need custom handlers, we are ok with the way initiativeblog.com engine is handling these requests but we need custom activities to be done during the processing phase.
So it looks like we can solve it using HTTPModule. initiativeblog.com Writing HTTP Modules (part 1) - The IHttpModule Interface, A Custom HTTP Module You register a new HTTP module by adding an entry to the httpModules> section of the configuration file.
The overall syntax of the httpModules> section closely resembles that of HTTP handlers. Custom headers or footers Because you can modify the outgoing response, you HTTP modules therefore let you examine incoming requests and take action based on the request.
They also let you examine the outgoing response and modify it. The general process for writing an HTTP module is as follows. You can also create custom HttpModules. You can create a custom HttpModule using a simple class which implements IHttpModule interface.
This interface provides two method - Writing Honest Methods in C# Dynamic Binding in C# Building Angular Applications using initiativeblog.com Core Angular CLI Template C# , and - New Features .
The two most common tools for reuse in initiativeblog.com are: User Controls and custom, compiled server controls for user interface elements and functionality. In fact, each time you add an initiativeblog.com Web page to your project, you are essentially writing a HTTP handler.
snippet shows the actual setting you'll need to use to . You can also create custom HttpModules. You can create a custom HttpModule using a simple class which implements IHttpModule interface. You can create a custom HttpModule using a simple class which implements IHttpModule interface.